Protective mask



FIG. 1 is a perspective view of a protective mask showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

In the drawings, the broken lines in FIG. 3 depict a portion of the design that form no part of the claim. 

The ornamental design for a protective mask, as shown and described. 